Valve has issued Counter-Strike gambling sites with a letter requesting they change their business practices to fall in line with Steam's terms or face further action, which could include account termination, reports Kotaku.
Here's the letter in full, confirmed by Valve to Kotaku as being legitimate.
"We are aware that you are operating one of the gambling sites listed below. You are using Steam accounts to conduct this business. Your use of Steam is subject to the terms of the Steam Subscriber Agreement ("SSA"). Under the SSA Steam and Steam services are licensed for persona, non-commercial use only. Your commercial use of Steam accounts is unlicensed and in violation of the SSA.
"You should immediately cease and desist further use of your Steam accounts for any commercial purposes. If you fail to do this within ten (10) days Valve will pursue all available remedies including without limitation terminating your accounts."
Some CS:GO gambling sites have already said action is being taken. CSGO2x said it "will be making some changes over the next week, in light of the statement released by Valve, to comply with the issues they addressed".
CSGO500 is also looking to bring its practices in line with Steam's terms of service.
"Our main goal here at CSGO500 is to provide an enjoyable service for our users that is both legitimate and interactive," said the site. "This will continue to be our goal, as we plan on adjusting to the upcoming limitations set by Valve. We assure our users that an alternative is already being worked on, one that will comply with Steam's Terms of Service."